Nearly 350 people, including schoolteachers, doctors and actors, have been arrested in what Toronto police say was one of the biggest ever child abuse raids.

Police said 386 children were rescued as a result of the sweeping investigation. More than 100 people were arrested in Canada and 76 in the US in an investigation dubbed Project Spade. More were arrested in other countries.

"It is alleged that officers seized hundreds of thousands of videos detailing horrific sexual acts against very young children, some of the worst that they have ever viewed," Inspector Joanna Beaven-Desjardins said.

Sixty-five men had been arrested in Australia as a result of the Canadian investigation, the federal police commander, Glen McEwen, said on Friday, and six children removed from harm. Police said the children were "rescued from child exploitation" but did not give further details.

Beaven-Desjardins said the investigation began with a Toronto man accused of running a company since 2005 that distributed child pornography videos.

Police allege Brian Way, 42, instructed people around the world to create the videos of children aged from five to 12, then distributed the videos via his company, Azov Films, to international customers. The videos included naked boys from Germany, Romania and Ukraine, which it marketed as naturist movies and claimed were legal in Canada and the US.

Police said they executed a search warrant at Way's company and home, seizing about 1,000 pieces of evidence: computers, servers, DVD burners, a video-editing suite and hundreds of movies.

Way was charged with 24 offences, including child pornography. He is in jail. Police also designated Azov Films as a criminal organisation, charging Way with giving directions on behalf of a gang.

Beaven-Desjardins said this was the first time in Canada that anyone had been charged with being a part of a criminal organisation in regards to child pornography.

Police said they began their investigation in 2010 and worked with Interpol in more than 50 countries, including Australia, Spain, Mexico, Norway and Greece. "This operation shows that international police co-operation works. Despite large amounts of material, and that this is time-consuming work, this shows that the internet is not a safe haven for crimes against children," Norwegian police spokesman Bjoern-Erik Ludvigsen said.

The US Postal Inspection Service said it began its investigation by accessing the company website and making undercover purchases.

Beaven-Desjardins said the investigation was continuing and believed more arrests would be made._